Limb stub-cutting mechanism

ABSTRACT

The rotary ring of a log barker has a flaring mouth carrying bits in radial planes for cutting limb stubs. Hooked ends of swinging arms rotate around a log as it is moved lengthwise to scrape off the bark.

0 United States Patent 1 [1 3,718,167

ervenak [4 1 Feb. 27, 1973 LIMB STUB-CUTTING MECHANISM [56] ReferencesCited Inventor: Peter J- Cervenak, Seattle, Wash. d [73] AssigleeNichlsn Manufacmring 314,876 3/1885 Poole etal. ..l44/208 E a wash-2,s02,494 8/1957 Nicholson ....l44/208 E [22] Filed: Jan. 24, 19723,333,615 8/1967 Robbins ..l44/208 E [21] Appl' 220328 PrimaryExaminer-Gerald A. Dost Related US. Application Data Attorney-RobertBeach [62] I Division of Ser. No. 84,056, Oct. 26, 1970, which is adivision of Ser; No. 627,067, March 30, 1967, Pat. [57] ABSTRACT3,536,265- The rotary ring of a log barker has a flaring mouth carryingbits in radial planes for cutting limb stubs. [52] US. Cl ..l44/2 Z,144/208 E Hooked ends of Swinging arms rotate around a l as [51] Int.Cl. ..A0lg 23/02 it is moved lengthwise to scrape off the bark [58]Field of Search ..l44/208 R, 208 E, 2 Z

3 Claims, 7 Drawing Figures sum 1 OF 2 PATENTEI] FEB 27 I973 PATENTEDFEB 2 7 I973 SHEET 2 OF 2 LIME STUD-CUTTING MECHANISM This applicationis a division of my application Ser. No. 084,056, for Log BarkerDelimber and Refuse- Reducing Mechanism, filed Oct. 26, 1970, which is adivision of my earlier application Ser. No. 627,067, for Log BarkerRefuse-Reducing Mechanism, filed Mar. 30, I967, which issued as U.S.Pat. No. 3,536,265.

A principal object of the invention is to remove limbs from logs beingbarked more readily and effectively and with less interference with thebarking operation than has been experienced previously.

More particularly, the invention relates. to an improved type of limband knot paring mechanism having inclined bits with an obtuse-angledcutting edge.

FIG. 1 is a longitudinal vertical section through a log barker of thepresent invention.

FIG. 2 is an elevation of the barker ring assembly viewed from thedischarge side, with parts broken away; and FIG. 3 is a correspondingelevation of the barker ring assembly viewed from the feed side.

FIG. 4 is an enlarged vertical longitudinal section through the barkerring assembly.

FIG. 5 is a detail bottom plan of a portion of a limb cutter bit takenon line 55 of FIG. 4;

' FIG. 6 is a detail section on line 66 of FIG. 5; and

FIG. 7 is a section on line 7-7 of FIG. 5.

The limb-cutting mechanism of the present invention can be applied tovarious types of rotary ring log barkers, representative examples ofwhich are shown in Nicholson US. Pat. No. 2,802,494 and in FIGS. 1, 2, 3and 4, in particular, of the drawings of this application. Logs L arefed lengthwise to such a barker by a feed conveyor 1 and the barked logis withdrawn from the barker by a discharge conveyor 2. The barker ringassembly is mounted on a plate 3 which can be suitably mounted andguided for elevational movement so that the center of the rotary barkerring 4 will coincide with the axis of the log L being barked. The barkerring is rotated around the log by a drive chain 5 engaging a drivesprocket 6 and teeth provided around the circumference of the barkerring.

Each log is fed through the throat 7 of the barker ring 4 to be engagedby scraper tips of the barker arms 8 which are mounted on the barkerring by pivots 9. These barker arms are swung in a direction about suchpivots to press their scraping ends against the log by hydraulic jacks10. Pressure of the barking tips of the arms against the log ismaintained by air under pressure in expandible air chambers 11 which arein communication with the respective jacks 10. Such log barker mechanismdescribed thus far in detail is not part of the present invention, butis simply representative of a typical rotary ring barker to which thepresent invention can be applied.

Projecting from the feed side of the rotary barker throat 7 is anannular flange or collar 12 forming a flared mouth through which a log Lis moved by the feed conveyor 1 into the barker ring throat. The anglebetween any portion of such mouth in a radial plane and the axis of thebarker ring 4 should be between 45 and 60 and preferably is about 55. Onthe flaring inner face of collar 12 are mounted elongated cutter bits 13having their lengths disposed substantially in radial planes. Thesecutter bits are spaced circumferentially of the barker ringsubstantially equidistantly, and their inner cutting ends project inwardbeyond the cylindrical surface of the throat 7.

The preferred shape of the cutter bit 13 is shown in detail in FIGS. 5,6 and 7. Each bit is of trapezoidal cross section, as shown in FIG. 7,having two parallel sides 13a and 13b disposed in planes parallel to theaxis of the barker ring, a side 13c perpendicular to such parallel sidesand in contiguous engagement with collar 12 and an inclined face 140.The face 14a of the bit connecting such parallel sides is inclinedrelative to them in a direction such that the leading side of the bit inthe direction of barker rotor rotation is wider than the trailing sideof the bit. Consequently, the leading face 13b of the bit and suchinclined joining face 14a converge to form an acute-angled cutting edge15a which preferably is approximately 60.

The inner end of the bit is beveled to provide an end surface 14b, shownin FIGS. 5 and 6, which will form a cutting edge 15b that issubstantially parallel to the axis of the rotary ring. The bevel betweenthe leading face 13b of the bit and the bit end face 14b again is suchthat the angle of the cutting edge 15b is acute and preferably about 60.The two cutting edges 15a and 15b intersect to form an obtuse angledcorner 15c, having an angle between and 135, depending upon the slope ofthe inner face of collar 12. Such angle preferably is approximately As alog L is fed by the conveyor 1 into themouth of the barker ring as shownin FIG. 1, the cutting edges 15a and 15b will engage and trim off anybranch stubs or other protuberances projecting outward to a distancebeyond the circle defined cooperatively by the cutting edges 15b of theseveral bits. A sufficient number of these bits should be provided tocut such projections effectively, and 16 of such bits has been found tobe a satisfactory number. Disposition of the lengths of the cutting bitssubstantially in radial planes of the barker rotor parallel to the axisof the rotor provides a strong cutting end, and one which does aneffective cutting job. In particular, a long cutting edge is afforded byarranging the cutting edge sections 15a and 15b at an obtuse angle, asshown best in FIG. 6, instead of the cutting edge sections forming aright angle like the cutting edge sections of the cutter bits shown inthe prior Nicholson US. Pat. No. 2,802,494.

The limb refuse cut by the bits 13 and the bark refuse scraped from thelog by the barker arms 8 in the form of discrete fragments falls intothe circular pit 16 shown in FIG. 1, which is located directly beneaththe barker. Across the lower portion of this pit extends a bridge 17which may be in the form of a channel having its edge flanges extendingupwardly. This bridge preferably extends diametrically across the pit sothat it serves to support a bearing for the upper end of an uprightshaft 18 located centrally of the pit. This shaft carries a hub 19 onwhich is mounted a rotor disk 20 of a hog.

The upright shaft 18 carries a pulley 21 which is connected by severalV-belts 22 to a drive pulley 23.This drive pulley can be driven by anysuitable drive mechanism such as represented by a shaft 24.

On opposite sides and opposite ends of the bridge 17 are mountedstationary shearing bars 25, the lower edges of which constituteshearing edges. Movable shearing bars 26 are carried by the rotor plate20 in positions to coact with the stationary shearing bars 25 as therotor rotates.

Beneath each movable shearing bar 26 is a vane 28 extending radially ofthe rotor, which acts to sweep the hogged waste material rotationallywithin the casing of the hog including an upright circumferential wall29, preferably of considerably greater extent than the wall of the pit16, a bottom wall 30 and an annular top wall 31 bridging between the pitand the circumferential wall 29 of the hog.

To prevent limb and bark refuse from lodging on the bridge 17, it ispreferred that it be capped by a ridged cover 33 held in place by bolts34. The ridge shape of such cover deters accumulation of refuse on thebridge, but in addition, flow of air drawn through the hog by movementof the vanes 28 will tend to sweep downward past opposite sides of thebridge and remove material from the ridged cover.

I claim:

1. Limb stub-cutting mechanism for a log barker having a rotary barkerring through which a log can be fed lengthwise, comprising a flangehaving a generally frustoconical surface flaring outwardly from theinfeed side of the barker ring toward logs being fed to the barker ringand carried by the barker ring, and a plurality of elongated cutter bitscarried by said flaring flange with their lengths inclined generallyparallel to said flaring surface and in substantially radial planes ofthe barker ring for cutting limb stubs from a log moving through thebarker ring.

2. The limb stub-cutting mechanism defined in claim 1, in which eachcutter bit has a cutting edge including a first section on the inner endof the bit extending substantially parallel to the axis of the barkerring and a second section inclined outwardly from said first sectiontoward the feed end of the barker ring, said two cutting edge sectionsbeing disposed at an obtuse angle.

3. The limb stub-cutting mechanism defined in claim 2, in which theobtuse angle between the two cutting edge sections of each bit isapproximately

1. Limb stub-cutting mechanism for a log barker having a rotary barkerring through which a log can be fed lengthwise, comprising a flangehaving a generally frustoconical surface flaring outwardly from theinfeed side of the barker ring toward logs being fed to the barker ringand carried by the barker ring, and a plurality of elongated cutter bitscarried by said flaring flange with their lengths inclined generallyparallel to said flaring surface and in substantially radial planes ofthe barker ring for cutting limb stubs from a log moving through thebarker ring.
 2. The limb stub-cutting mechanism defined in claim 1, inwhich each cutter bit has a cutting edge including a first section onthe inner end of the bit extending substantially parallel to the axis ofthe barker ring and a second section inclined outwardly from said firstsection toward the feed end of the barker ring, said two cutting edgesections being disposed at an obtuse angle.
 3. The limb stub-cuttingmechanism defined in claim 2, in which the obtuse angle between the twocutting edge sections of each bit is approximately 125* .